Horizontal strapping machine

ABSTRACT

A stacking and strapping apparatus is configured to stack a first load layer on a pallet, horizontally strap the load, stack a second load layer on the first load layer and horizontally strap the second load layer. The apparatus includes a frame, a sealing head operably mounted to the frame, a feed head operably mounted to the frame and a strap chute mounted to the frame. The strap chute is stationary and is fixedly mounted to the frame in a generally horizontal plane and has an opening therein for receiving the sealing head. The strap chute defines the boundaries of a vertical path for movement of the pallet, the first load layer and the second load layer. A draw plate is disposed above the strap chute. The draw plate is configured to receive the first load layer or the second load layer and to move between a loading position in which the first or second load layer is loaded onto the draw plate and a withdrawn position in which the draw plate moves to position the first load layer on the pallet or to position the second load layer on the first load layer. The draw plate is configured to move back to the loading position following transfer of the first load layer or the second load layer. A lift plate is disposed below the strap chute and draw plate. The lift plate is adapted to receive the pallet and to receive a load on the pallet. The lift plate moves downwardly to position the first load layer at the strap chute, moves up to receive the second load layer and moves downwardly again to position the second load layer at the strap chute.

BACKGROUND OF THE INVENTION

The present invention is directed to a horizontal strapping machine. More particularly, the present invention is directed to a horizontal strapping machine that is mounted under the draw plate of a palletizer.

Strapping machines are in widespread use for securing straps around loads. In many instances, strap is required to be positioned horizontally about a load that is stacked onto an adjacent lower layer of product. Such packaging arrangements often include multiple layers of product on, for example, a pallet, to facilitate handling and transport. The process of horizontal strapping is typically a stabilizing process.

In known horizontal strapping machines, the strap head and strap chute are horizontally oriented and move in a vertical path up and down to apply the strap to the load. While this is an effective method for applying the strap, it is a time consuming process and requires a mechanically complex system for moving the strapping head and chute, as well as the necessary drives for feeding and tensioning the strap and forming the strap “weld”.

Such a strapping system can also require considerable headroom over and above that needed for the stacked product. As such, any overhead transport processes are limited by the space needed for the stacking and strapping equipment.

Accordingly, there is a need for a horizontal strapping machine that effectively integrates into stacking (or palletizing) operations. Desirably, such a strapper includes a vertically stationary strap chute and strapping head. Most desirably, such a strapping machine can be used with an overhead transport system in which product is conveyed at an elevated height within a facility.

BRIEF SUMMARY OF THE INVENTION

A horizontal strapping machine is integrated into a stacking or palletizing apparatus. Such an apparatus is configured to stack a first load layer on a pallet, strap the load and stack a second load layer on the first load layer and strap the second load layer. The strapper includes a frame, a sealing head operably mounted to the frame, a feed head operably mounted to the frame, and a strap chute mounted to the frame.

The strap chute is mounted to the frame in a generally horizontal plane and is fixed to the frame. The strap chute has an opening therein such that the sealing head is disposed within the strap chute opening. The strap chute defines vertical planes that further define a path for movement of the pallet and the first and second load layers.

A draw plate is disposed above the strap chute. The draw plate is configured to receive the first load layer or the second load layer and to move between a loading (closed) position in which the first or second load layer is loaded onto the draw plate and a withdrawn (open) position in which the draw plate moves to position the first load layer on the pallet or to position the second load layer on the first load layer. The draw plate is configured to move back to the loading position following transfer of the first load layer or the second load layer.

A lift plate is disposed below the strap chute and draw plate. The lift plate is adapted to receive the pallet and to receive a load on the pallet. The lift plate is further configured to move downwardly to position the first load layer at the strap chute, move up to receive the second load layer and move downwardly again to position the second load layer at the strap chute.

In a present strapper, the sealing head and the feed head are independently operably mounted to the frame. In such an arrangement, the strap chute is fixedly mounted to the frame.

A sensor can be operably connected to the draw plate for moving the draw plate from the loading position to the withdrawn position when the presence of the pallet or a load layer is sensed below and proximal to the draw plate.

These and other features and advantages of the present invention will be readily apparent from the following detailed description, in conjunction with the claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:

FIG. 1 is a side view of an exemplary packaging machine having a palletizer and a horizontal strapper in accordance with the principles of the present invention;

FIG. 2 is a front view of the exemplary packaging machine of FIG. 1;

FIG. 3 is a top view of the packaging machine;

FIG. 4 is a perspective view of the strapper section of the machine;

FIG. 5 is a perspective view of the strap chute, chute frame and strapping head;

FIG. 6 is a top view of the strap chute; and

FIG. 7 illustrates the relative positions of the lift plate, strap chute and draw plate within the palletizer.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in various forms, there is shown in the figures and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.

It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.

Referring to the figures and in particular to FIG. 1, there is shown a packaging machine 10 that includes horizontal strapping machine or strapper 12 embodying the principles of the present invention. The strapper 12 mounted generally to a machine frame 15 within the packaging machine which includes a palletizer 14. The palletizer 14 includes a reciprocating receiver 16 for receiving pallets P onto which one or more load layers L₁, L₂ are placed. The present machine system 10 includes a lift plate 16 that serves as the receiver and that moves vertically to receive the first load (in a layer L) on the pallet P and move downwardly to receive a second load (layer L₂) on the first load layer L₁. This movement and load layering continues until a desired number of layers are accumulated on the pallet P.

In order to position the first layer L₁ of product on the pallet P and subsequent layers L₂ on a previous layer, the machine 10 includes a draw plate 18. The draw plate 18 is essentially a sliding platform on which the product is stacked (in a single layer, as in layer L₃ in FIG. 7), that is positioned above the lift plate 16. As the draw plate 18 is moved (horizontally) out from under the load layer, the product is slid off of the draw plate 18 onto the pallet P or product stack L.

The strapper 12 is mounted at an upper end of the frame 15 and includes a strapping head 20, where strapping head 20 refers, generally, to a feed head 22 and a sealing head 24, collectively. In a present strapper 12, the feed head 22 and sealing head 24 can be modular components, such as those described in Flaum et al., U.S. Pat. No. 6,584,892, which patent is commonly assigned with the present application and is incorporated herein by reference.

The strapper 12 further includes a frame 26, a strap chute 28, a strap supply or dispenser 30 and a control system 32. The control system 32 can be integrated with the overall packaging machine controller to coordinate operation of the entire system. As will be understood by those skilled in the art, the feed head 22 is that assembly within the strapping machine 12 that conveys the strap material S through the sealing head 24 and into the chute 28. The strap material S traverses through the chute 28 back around to the sealing head 24. In the illustrated machine 10, the strap S is conveyed through the sealing head 24, into and around the far end of the chute 28 and back to the sealing head 24. The feed head 22 then retracts the strap S until it encircles and lies on the load L. Following retraction, the strap S is tensioned, severed (to separate the strap S around the load L from the strap supply, e.g., from the strap S on the dispenser 30) and sealed to itself, as by welding or the like.

In the present arrangement, the horizontal strap chute 28 defines a load travel path as indicated at 34. That is, the pallet P (with the load L thereon) travels up and down within the bounds defined by the inner periphery of the strap chute 28.

The modular strapping head 20 components 22, 24, are mounted to the frame 26 independently of one another so that either can be removed from the frame 26 to, for example, replace the head, conduct maintenance or the like, as described in the aforementioned patent to Flaum et al. The modular components 22, 24 can be mounted on or to a carriage 36 that is mounted to the frame 26. In such an arrangement, the carriage 36 is configured to move, toward and away from the load (as indicated by the double-headed arrow at 38), during the strapping operation, e.g., during tensioning of the strap S around the load L.

The present strapper 12 is arranged unlike known devices. Referring to FIGS. 2 and 7, the palletizer 14 is located above the strapping head 20, with the draw plate 18 disposed above the strap chute 28. As such, strapping of the load L occurs when the load L is moving in the downward direction. In operation, the load, e.g., L₃, is moved onto the draw plate 18. The lift plate 16 with the pallet P thereon is moved up to the bottom of the draw plate 18 (or, if there is one or more load layers L₁, L₂ on the pallet P, the lift plate 16 with the pallet P and with the layer(s) L₁, L₂ is moved up to the draw plate 18), until it touches the bottom of the draw plate 18 or is otherwise sensed (such as by a sensor 40) to be in position for receiving a load layer. The draw plate 18 then withdraws and the load layer L₃ is conveyed onto the pallet P or lower layer L₂. The lift plate 16 then descends and the draw plate 18 moves back to the loading position. The lift plate 16 moves the just placed load into the strap chute 28.

The strapping operation is then carried out (i.e., feeding strap S around the chute 28, retracting the strap S onto the load L, tensioning, severing and sealing the strap S). At the same time that the “lower” load layer is being strapped, a next upper load L₃ is moved onto the draw plate 18 and readied for transfer onto the “lower” layer L₂. Once the load L₃ is ready and strapping of the lower layer is complete, the lift plate 16 raises the pallet P (and load L) to touch the bottom of the draw plate 18 (or until the load L is otherwise sensed). The draw plate 18 then withdraws and the load L₃ is transferred onto the lower layer L₂ for subsequent strapping. Following the loading of a desired number of load layers L, the lift table 16 fully descends and the loaded pallet P is transferred off of the lift table 16 for subsequent handling.

All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.

In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.

From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover all such modifications as fall within the scope of the claims. 

1. A stacking and strapping apparatus configured to stack a first load layer on a pallet, strap the load and stack a second load layer on the first load layer and strap the second load layer, comprising: a frame; a sealing head operably mounted to the frame; a feed head operably mounted to the frame; a stationary strap chute mounted to the frame, the strap chute mounted to the frame in a generally horizontal plane, the strap chute having an opening therein and the sealing head being disposed within the strap chute opening, the strap chute defining boundaries of a vertical path for movement of the pallet, the first load layer and the second load layer; a draw plate disposed above the strap chute, the draw plate configured to receive the first load layer or the second load layer and to move between a loading position in which the first or second load layer is loaded onto the draw plate and a withdrawn position in which the draw plate moves to position the first load layer on the pallet or to position the second load layer on the first load layer, the draw plate configured to move back to the loading position following transfer of the first load layer or the second load layer; a lift plate disposed below the strap chute and draw plate, the lift plate adapted to receive the pallet and to receive a load on the pallet, the lift plate further configured to move downwardly to position the first load layer at the strap chute, move up to receive the second load layer and move downwardly again to position the second load layer at the strap chute.
 2. The stacking and strapping apparatus in accordance with claim 1 wherein the sealing head and the feed head are independently operably mounted to the frame.
 3. The stacking and strapping apparatus in accordance with claim 1 wherein the strap chute is fixedly mounted to the frame.
 4. The stacking and strapping apparatus in accordance with claim 1 including a sensor operably connected to the draw plate for moving the draw plate from the loading position to the withdrawn position when the presence of the pallet or a load layer is sensed below and proximal to the draw plate.
 5. A strapper for use with a palletizer, the palletizer configured to stack a first load layer on a pallet, strap the load and stack a second load layer on the first load layer and strap the second load layer, the palletizer including a frame, a draw plate configured to receive the first load layer or the second load layer and to move between a loading position in which the first or second load layer is loaded onto the draw plate and a withdrawn position in which the draw plate moves to position the first load layer on the pallet or to position the second load layer on the first load layer, and a lift plate disposed below the draw plate, the lift plate configured to move up and down between the uppermost position and a lowermost position, the lift plate adapted to receive the pallet and to receive a load on the pallet and to move downwardly with the load and pallet thereon, the strapper comprising: a stationary strap chute rigidly mounted to the frame, the strap chute mounted to the frame in a generally horizontal plane, below the draw plate and above a lowermost position of the lift plate, the strap chute defining boundaries of a vertical path for movement of the pallet, the first load layer and the second load layer, the strap chute having an opening therein and the sealing head being disposed within the strap chute opening; a sealing head operably mounted to the frame; and a feed head operably mounted to the frame, wherein the first load layer on a pallet is moved downwardly into the strap chute where the first load layer is strapped and wherein a second load layer is stacked on the first load layer and is moved downwardly into the strap chute where the second load layer is strapped.
 6. The strapper in accordance with claim 5 wherein the sealing head and the feed head are independently operably mounted to the frame.
 7. The strapper in accordance with claim 5 wherein the strap chute is fixedly mounted to the frame.
 8. The strapper in accordance with claim 5 including a sensor operably connected to the draw plate for moving the draw plate from the loading position to the withdrawn position when the presence of the pallet or a load layer is sensed below and proximal to the draw plate. 